Hydrothermal Aging of ATZ Composites Based on Zirconia Made of Powders with Different Yttria Content

Abstract

The presented work concerns the development and investigation of three different grades of ZrO2 materials containing Al2O3 particles (ATZ-Alumina Toughened Zirconia ceramics with 2.3–20 vol.% of alumina). The zirconia powders containing 3 mol.% of yttria were synthesized by a precipitation/calcination method and fabricated from two different zirconia powders with different yttria content. Then, the selected ATZ composites (ATZ-B, ATZ-10 and ATZ-20) were prepared by means of conventional mixing, compacting and sintering at 1450 °C for 1.5 h. The phase composition, microstructure, relative density and basic mechanical properties were determined. Uniform microstructures with relative densities over 99% of theoretical density, hardness values between 12.0–13.8 GPa, flexural strength up to 1 GPa and outstanding fracture toughness of 12.7 MPa⋅m1/2 were obtained. The aging susceptibility of alumina toughened zirconia materials, as a consequence of hydrothermal treatment, was investigated. The aim of this study was to determine the influence of LTD (low temperature degradation) on the tetragonal to monoclinic phase transitions and on the flexural strength of hydrothermally aged specimens. The results were compared to those obtained for commercially available tetragonal zirconia-based materials containing 3 mol.% of yttria. This research shows that ATZ composites that have excellent mechanical properties and sufficient hydrothermal aging resistance can be attained and later used in technical and biomedical applications.

The Influence of the Phase Arrangement of ATZ Composites on Their Wear Rate Under Ball-on-Disc Tests

“…Materials investigated during sliding wear tests were three composites from alumina toughened zirconia (ATZ) material's family. Investigated materials were manufactured utilizing a specific idea of zirconia matrix preparation described more detail in [19,20]. The general idea was to prepare composite mixing two zirconia powders: pure nanometric ZrO2 one and a solid solution of 4 mol.% Y2O3 in ZrO2 powder.…”

“…However, composite powder processing and, consequently, sintering procedure could also significantly influence the final phase composition, microstructure and residual stress state. The aim of the presented paper was to use a zirconia matrix in the ATZ composite as a specific material with a fine microstructure and high tendency to the tetragonal to monoclinic phase transformation, which could assure a high level of mechanical and tribological properties [14][15][16][17][18].…”

Wear behaviour of alumina-toughened-zirconia composites with different phase arrangement under ball-on-flat tribological tests

“…Materials investigated during sliding wear tests were two composites from alumina toughened zirconia (ATZ) material's family. Both investigated materials were manufactured utilising a specific idea of zirconia matrix preparation described in more detail in [19,20]. The general idea was to prepare composite mixing of two zirconia powders: pure nanometric ZrO 2 one and a solid solution of 4 mol.% Y 2 O 3 in ZrO 2 powder.…”

“…ion exchange [13]. However, composite powder processing and, consequently, the sintering procedure could also significantly influence the final phase composition, microstructure, and residual stress state [14][15][16][17][18]. The aim of the presented paper was to use a zirconia matrix in the ATZ composite as a specific material with a fine microstructure and a high tendency to the tetragonal to monoclinic phase transformation, which could assure a high level of mechanical and tribological properties.…”

Prediction of Hardness, Flexural Strength, and Fracture Toughness of Zro2 Based Ceramics Using Ensemble Learning Algorithms

“…Products made of such ceramics can operate under high temperatures, high pressure, corrosion, and friction conditions. Yttria stabilized zirconia ceramics are widely used for the manufacture of bearings [7], friction plates, valve plates, ball valves, pipeline linings, nozzles, directional drilling tool components, control valves, pump plungers, metering pump parts, moulds, protective tubes of thermocouples, solid oxide fuel cells [8][9][10][11][12] and thermal protective coatings [9,10,13]. Zirconia is widely used to manufacture internal combustion engine components (bearings, rollers, dies, pushers, valves, and fuel injectors) [14,15].…”